cmd/compile: negative types are allowed, but will not be negative during program execution, with boundary checking #64895
Description
Go version
go version devel go1.22-78b42a5338a Fri Dec 8 03:28:17 2023 +0000 linux/amd64
What operating system and processor architecture are you using (go env)?
set GO111MODULE=auto
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\26454\AppData\Local\go-build
set GOENV=C:\Users\26454\AppData\Roaming\go\env
set GOEXE=.exe
set GOEXPERIMENT=
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMODCACHE=D:\file\gofile\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=D:\file\gofile
set GOPRIVATE=
set GOPROXY=https://goproxy.cn,direct
set GOROOT=C:\Users\26454\.go\current
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLCHAIN=local
set GOTOOLDIR=C:\Users\26454\.go\current\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=devel go1.22-f6509cf Thu Dec 21 00:15:58 2023 +0000
set GCCGO=gccgo
set GOAMD64=v3
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=
set GOWORK=
set CGO_CFLAGS=-O2 -g
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-O2 -g
set CGO_FFLAGS=-O2 -g
set CGO_LDFLAGS=-O2 -g
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=D:\tmp\go-build1429133840=/tmp/go-build -gno-record-gcc-switchesWhat did you do?
package main
type s struct {
str string
i int
}
func main() {
var l s
l.str = "100"
for l.i < len(l.str) {
switch l.str[l.i] {
case '1':
l.i++
case '0':
for i := l.i + 1; i < len(l.str); i++ {
_ = l.str[l.i]
}
}
}
}What did you expect to see?
No Boundary check.
What did you see instead?
Have Boundary check.